Mutations in the human gene encoding cadherin23 (CDH23) cause Usher syndrome type 1D (USH1D) and nonsyndromic hearing loss. Individuals with Usher syndrome type I have profound congenital deafness, vestibular areflexia and usually begin to exhibit signs of RP in early adolescence. In the present stu
Identification and in vitro expression of novel CDH23 mutations of patients with Usher syndrome type 1D
✍ Scribed by Benigna von Brederlow; Hanno Bolz; Andreas Janecke; Alicia La O Cabrera; Günther Rudolph; Birgit Lorenz; Eberhard Schwinger; Andreas Gal
- Publisher
- John Wiley and Sons
- Year
- 2002
- Tongue
- English
- Weight
- 307 KB
- Volume
- 19
- Category
- Article
- ISSN
- 1059-7794
No coin nor oath required. For personal study only.
✦ Synopsis
Communicated by Albert de la Chapelle
Usher syndrome (USH) is a group of autosomal recessive sensory disorders characterized by progressive retinitis pigmentosa (RP) and sensorineural hearing impairment. Usher syndrome type 1 (USH1), with additional vestibular dysfunction, represents the most severe form and shows extensive allelic and non-allelic heterogeneity. At least six USH1 loci exist (USH1A-F), and four of the underlying genes have been identified. Recently, a novel gene, cadherin 23 (CDH23), was shown to be mutated in USH1D. We performed mutation screening by single strand conformation polymorphism (SSCP) analysis and direct sequencing on 33 USH1 patients previously excluded for USH1B and USH1C. On eight disease alleles of four patients, four different mutations were identified, three of them novel (c.6933delT, c.5712G®A, and IVS45-9G®A). Exon trapping experiments were performed with two mutations. In the case of a c.5712G®A transition of the last base of exon 42, that is an apparently synonymous mutation, skipping of exon 42 was observed. By the mutation IVS45-9G®A, a novel splice acceptor site was created and the insertion of 7 intronic bp was observed. Two mutations, IVS45-9G®A and the previously described IVS51+5G®A, were each found in more than one patient. Haplotype analysis by SNPs within CDH23 suggests common ancestors for each of the mutations. Among the total of 52 USH1 cases studied by us, CDH23 mutations account for about 10% of all disease alleles. Our results further suggest that in patients with a typical USH1D phenotype, a significant portion of CDH23 mutations leads to premature termination of translation or loss of numerous amino acid residues, with a high frequency of changes causing aberrant splicing of CDH23 mRNA.
📜 SIMILAR VOLUMES
## Communicated by Andreas Gal Usher syndrome type II (USH2) is an autosomal recessive disorder, characterised by moderate to severe high-frequency hearing impairment, normal balance function and progressive visual impairment due to retinitis pigmentosa. Usher syndrome type IIa, the most common su
## Communicated by Mireille Claustres Shwachman-Diamond syndrome (SDS) is a rare autosomal recessive disease, mainly characterized by exocrine pancreatic insufficiency, hematological dysfunction and skeletal abnormalities. The SDS disease locus was mapped to chromosome 7q11 and disease-associated m
Usher syndrome is a heterogeneous autosomal recessive trait and the most common cause of hereditary deaf-blindness. Usher syndrome type I (USH1) is characterised by profound congenital sensorineural hearing loss, vestibular dysfunction, and prepubertal onset of retinitis pigmentosa. Of the at least
We report 9 new mutations in German patients presenting with classical Marfan syndrome. All mutations occur in exons with calcium-binding (cb) epidermal growth factor-like (EGF) domains. Five mutations are missense involving exons 12, 27, 30, 44, and 52 with the resultant substitution of cysteine by
Alagille syndrome (AGS) is an autosomal dominant disorder characterized by five major symptoms: cholestasis, vertebral deformity, heart malformations, ocular defects and peculiar facial appearance. The previously described Jagged1 (JAG1) gene on chromosome 20p12 has been identified as being responsi